In structural applications where surface contact is involved (e.g., submarine mast fairing guiderails and carrier landing cable-guiding sheaves), the performance and useful life of suitable materials are chiefly determined by their surface properties such as wear resistance and hardness. Aluminum-based materials are attractive for these types of structural applications in the aerospace, military, and transportation industries due to their light weight, high strength-to-weight ratio, and good corrosion resistance. However, the applications for aluminum-based materials are significantly limited, due to their poor surface properties, e.g., poor wear resistance, evidenced as severe adhesive wear. Other materials, such as magnesium and titanium, also suffer from poor wear resistance, and therefore, applications with these materials are similarly limited.
Although Al2O3—Al composites containing a relatively high concentration (15 volume percent) of Al2O3 nanoparticles have been found to exhibit superior wear resistance by showing both significantly lower wear rates and desired abrasive wear, direct usage of these bulk nanocomposites is limited because of the resulting reduction in ductility and thermal conductivity. In addition, the bulk process (mechanical alloying+hot isostatic pressing) typically used to manufacture these Al2O3—Al composites is time- and energy-intensive, and has stringent part size and geometry restrictions.
It therefore would be desirable to provide new and improved nanoparticle-reinforced composites that provide a hard, strong, wear-resistant surface, while still maintaining the ductility and thermal conductivity of the substrate material that, by itself, otherwise has poor surface properties. It would also be desirable to provide new and improved methods for making these composites.